The present invention will be described for a gripper, within an automated handler which palletizes and/or depalletizes parts within a manufacturing line, as an example end effector of an automated equipment used in a manufacturing line. However, as would be apparent to one of ordinary skill in the art from the description herein, the present invention may be used for any other type of automated end effectors such as cutting or grinding tools, welding guns, or other type of automated pneumatic or servo-driven parts within any type of automated equipment that requires proper alignment of the end effector.
Referring to FIG. 1, an automated handler 100 is used in a manufacturing line for assembling an article of manufacture. The automated handler 100 includes a gripper 106 which is an example of an automated end effector within an automated equipment used in a manufacturing line. The automated handler 100 includes a base 102, a movable arm 104, and the gripper 106. The position of the gripper 106 of the automated handler 100 is adjusted via the movable arm 104 such that the gripper 106 may reach down and grip a part 108 for picking up the part 108 to be incorporated in the article of manufacture.
A pallet 110 holds a plurality of parts 108, 112, and 114. Referring to FIG. 2, a top view of the pallet 110 shows a plurality of cells 202, 204, 206, 208, 210, 212, 214, 216, and 218. Typically, each of the plurality of cells holds a corresponding one of a plurality of parts. The pallet 110 is used to transfer the plurality of parts through the manufacturing line during a manufacturing process. For example, the plurality of parts may be automotive parts within an assembly line during manufacture of automotive systems.
The gripper 106 may reach down and grip a part from the pallet 110 for picking up the part to be incorporated in the article of manufacture. Alternatively, the gripper 106 may reach down to place a part into the pallet 110 to transfer parts from a manufacturing line into the pallet 110.
In either case, referring to FIG. 3, the automated handler 100 may not be properly aligned with the cells of the pallet 110. For example, some manufacturing processes heat the plurality of parts within the pallet 110 to high temperatures such as 500.degree. C. In addition, the pallet 110 is reused for heating and cooling of a large number of parts. With such repeated heating and cooling of the pallet 110, the pallet 110 warps in shape with time such that the gripper 106 is no longer properly aligned with the cells of the pallet 110.
In any case, when the gripper 106 is not properly aligned with the cells of the pallet 110, the gripper 106 collides with a part within the pallet 110 or any other part of the pallet 100 to result in an undesirable crash. In the prior art automated handler system, the crash of the gripper 106 into a part is detected. Upon detection of the crash in the prior art, the mechanism for holding the gripper from the automated handler 100 is loosened to minimize the stress of force applied on the part and on the gripper from the crash. For example, an air chamber of the prior art holding the gripper 106 is depressurized upon detection of a crash to minimize the stress of force applied on the part and on the gripper from the crash. In addition, an operator is then notified of the crash.
Unfortunately, the automated handler 100 of the prior art is manually reset after a crash. The position of the gripper 106 is manually readjusted to be properly aligned with respect to the position of a part within the pallet 110 to be picked up. The components on the automated handler 100 of the prior art are also manually reset to begin operation of the automated handler 100 again after a crash. However, such manual resetting of the automated handler 100 after a crash results in a relatively long down-time and high labor costs during the manufacturing process.
Thus, a mechanism for preventing an undesired crash of an end effector such as the automated handler 100 is desired